If the odds are 1/1 then you get the money you already bet back PLUS that amount again, eg: Bet 1000 points on Diego, he wins, so you get the 1000 back PLUS ANOTHER 1000, leaving you with 1000 more than before.

Well I only got 500 back on a 1/1 bet. Which is what I put down. Explain that

If you bet on the guy that's expected to win with 1:1 odds, and the guy wins you multiply your stake by 1.0. If you bet on the guy that's expected to loose by a 2:1 margin and and the underdog wins, you multiply your wager by 2.0.

Ex. Liddell vs. Ortiz is currently running at 3:1 in favor of Liddell. If you bet say 1000 points on Ortiz and he wins (which he will not) you triple your money. But because Liddell is expected to win it would be a push if you bet on him.